1. Field of the Invention
The field of this invention resides in the area of electric cells.
2. Description of the Prior Art
Hall's electric cells are well known in the prior art. Such cells have a metal or semiconductor strip with a source of electricity providing a control current to each end thereof causing an electrical potential at the ends of the strip. A magnetic field is provided at a direction generally perpendicular or at least at any angle except 0.degree. to the direction of the control current. Electrons move because of the electric field in the strip in combination with the magnetic field which changes the direction of the movement of such electric charges in accordance with Lorentz'Law. For this reason, an electrical potential difference or Hall voltage is found on the sides of the strip where a current is generated. For example, on a copper strip, an electric field of 1.times.10.sup.-5 volts/cm can be achieved. When using semiconductors, the electrical potential difference is much greater. Whether an electrical potential difference is positive or negative depends upon the sign of the electrical charges and the direction of the magnetic fields. Hall's electric cells are utilized for precision measurements of magnetic fields and also for judging the number and mobility of electrons or holes in metals or semiconductors per unit volume.